Fuel briquette and method of making same



r B. t. u. by the driving off of volatile com Patented Apr. 24, 1928.

*. UNITED .sTAre-s.

- AT NT:- IE+ v moon SHOTWELL nonEson, or rnnnrno'ron, NEwjJnnsnY.

FUEL BRIQUETTE ANDMETHOD OF MAKING SAME.

No Drawing.

In the manufacture of fuel briquettes from coal dust or coal in other finely sub-y divided form, it is commonpracticeto add a binding agent, pressthe mixture into the desired form and bake or otherwise heat the briquettes to dry or harden them; Most binding agents used forthis purposeare of lower fuel value than the coal so that the average B. t. u. of the mixtureisreduced and the heating tends to further reduce the bustible constituents of the coal. L v Various attempts. have been made to render fine coal better adapted for use as fuel and to increase the B. t. u. thereofby value, due to the fact that; it retains acomparatively large percentage of the oil and other volatile. parts of the, fuel mixture; it may be burned with comparatively little or no smoke; it has a hard outer wall or casing rendering it adapted for storage, shipment or rough handling; thecost of manufacture is comparatively low, due to the low temperature employed in the baking or hardening step of the process; and the product is commercially'very satisfactory. I

In'my improved processI add to the oil and coal dust mixture a solid miter-soluble quick hardening adhesive or binderwhich will unite with the small percentage of Water normally present in the oil and coal dust mixture, and will serve to give to the briquette the desired strength while the briquette is green, that is, after u it is pressed to the desired form 'or otherwise shaped, and before it is baked or hardened. During'the baking or hardeningprocess the temperature is kept coi'nparat ively low, that is, between 150 and 250 0;, which acts. to set the binder or adhesive which was added, to drive off the moisture, and to :ClllVQ Ollt the volatile combustible constituents of the surface portions of the briquette. The heating does not driveouttany considerable portion of thevola-tile combustibleconstituents Application filed September 26, 1924.) Serial No.-740,04 0.

from the interior ofcthe .briquette, but it serves to coke the outer surface parts so as,

toform a hard shell. v

The percentage of volatile briquette increases as the distance from the volatilematteris protected by the outer shellnot onlydurin jshipmentyandstorage, but

alsowhenther riquette 'is thrown onto, the

tire. {The oil andjother volatile constituents r 5 are not; driven oil? until after: the outer =surface ,of the ,"briquette begins 'to burn at a good white heat, and then are driven off,

matter in the v enter surfaceincreases, but the interior portion containing the highest percentage of comparatively slowly so that they are burned to yield'theinfull heating (value without producing a smoky flame. The percentage of ash in the briquette is lower than with the ordinary briquette, due to the presence of the oil constituent. v s a s I do not wish to be limited to any exact proportion ofgcoal dust and oil',ybut-have secured satisfactory resultswith the oil running as high as,20.per cent. .Either anthracite or bituminous coal may be employed,

and the coaldust may be used in the usual I form or may be: ground or crushed toa very much finer form,1and-in being mixed with theoil may produce a mixture analogous to or actually constituting an amalgam. What isknown asfTrent amalgam? may be used very satisfactorily. This includes about 80% to 82% very fine coal, 14% to 16% oil, and 2% to 4% moisture. v v 1 As a binding agent'to giveto the mixture its green strength, I preferably employ about 2%of lignone powder. resulting from the evaporation of sultite cellulose liquorto dryness. Such a powder acts toabsorb the small percentage of moisture presentin the oil-coal mixtureand thereby forms the adhesive tohold the mixture together, particularly whengreen. Instead of using this sulfite cellulose liquor powder or lignone, I may employ other dry quick-setting water-soluble adhesive, such as flour, ,dextrine or the like. I may employ other adhesives orbinders including moisture or water, but obviously it is desirableto add as little water "or other non-combustible matter as mpossible. In

forming the mixture into briquettes I preferor aperturein the form of'a' solidortubular rod or bar which maybe cut orbrokeninto sections or fshapes of the desired length.

harden the outer shell or surface portion. The shorterthe heating period the lower the manufacturing cost. lhe hea-t drives otli all of thewater and most'ofthe lighter oils, but these latter maybecon'densedand collected asitis of: courseunderstood that:the-heating is conductedout of contactwithtlre airt- By using 2% oflignonewith Trent almal' gain, theanth-racite coa-l of whiclr contained 4:%-t07% volatiles, Sl1LP1I1gjV1l3ll an augermachine and bakmgat'QOO C. until suitciently hard to. stand transportation, I have;

produced very satisfactory briquettes containing- 10% to 15% of combustible volatile constituents.-

Ihave discovered thatco'al or other mineralmatterhaving too higha fluid content of such a liquid as oil, bitumen, asphalt or other non-water-soluble adhes ve, can be mixed with lignone, liquid or dry, or: other quickesetting water-soluble adhesive, and formed into suitable briquettes in, an BXUIF sion machine, by forcing through a die by the use of a screw or auger.-

In the foregoing description I'liave used the term coal *dust""to include any form of coal or. other combustible mineral matter in finely subdivided form The coal particles may all pass a 20.0 mesh siev e, or the coal may be rincludebuckwheatcoal, to 80% ofwhich williremain on a 10 mesh sieve. In order to secure proper working in the extrusionmachinev itis important that the mixture be plastic, and the plasticity is greater when the finer grades of coal 'dustare used. Also by using the finer grades of coal dust, the briquette is made moredense and with smaller interstitial spaces between the coal particles and less of the volatile constituentszescape from the interior of the briquette during the heating operation.

Ihave used the term oil to include not only wnat is commonly known as oil, but also bitumen, asphalt or-other combustible liquid of the samegeneral type, and whether used-inthecrude form or obtained in the distillation or purificationcfnnineral oil, or distillation from coal, lignite or the like. The oil *serves as a non-water solublebinder to holdithedust togetheigas the non-volatilized portionsai'din uniting the particles during the heating. V

-Alth'ough the briquettes may be of solid form they are preferably made of tubular A method of forming briquettes which 1ncludes mixln'g a minera-lzfuel m granular or powdered form witha non-water-soluble adhesive binder, adding a water-solublead hesive, pressing the same into. suitable shapes, andheat ng the shaped massesto drive 011 the volatiles fromthe-exposed s-urfaces of such masses.-

A method of-makingbriquettes whichincludes mixing fine coal-with a liquid fuel,

adding a watersoluble adhesive, forming into suitable masses by exerting pressure thereon, and heating to distill off a portion only of the-liquid and to coke the su-r-faceportion.

i: A method-of making briquettes which includes mixingcoal dust with oil, adding; a solid adhesive, forming into suitable masses by exerting pressure thereon, and heating the forn'iedmasses to a tenipe aturc below 250 C.

5; A method of formi-ngbriquettes which includes adding li gnone to a mixture of coal dust and'oil, forming the mixture into suitable shapes and heating.

6. Amethod offorming briquettes which includes adding lignone to a mixture offine coal'and oil, forming the mixture-into suitable shapes and-heating at'a low temperature to drive offia portion only of tlre volatile constituents. v

7. Ainethodbf manufacturing briquettes which includes adding-lignone powder'to a mixture of fine aited-011,; forming masses of the mixture, and heating said iii-asses to a temperature not above. 250 C.

8. A method of forming briquettes which includes adding a small'percentageof' dry lignone to a mixture of coal dust and15% to ofoil, forming into suitable masses upon an extrusion machine, and heating. to distill ofi a portion only of'the oil.

9. A method of forming briquettes which includes adding asmall percentage ofdry adhesive inpowder form to a mixture of coal dust and from 15% to 20% ofoil, forming into suitable massesupon an extrusion machine, and heating suchmasses ,tocoke the outer'surface portion thereof but not-'to distill all of the oil from the inner portions.

10. A method of forming-briquettes Which includes mixing coal dust*vv itl-r15% to 20% of-a mineral oil, and approximately2% of dry lignone, forming the mixture into suittile matter from the surface portions, and

heating the sections tovharden the same.

12. The method of making fuel briquettes which includes forming a plastic massof finely subdivided solid fuel, substantially all of which will pass a 200 mesh screen and a binder, forcing said mass through an aperture to form a rod, subdividing the rod into sections, and heating the sections to drive off volatile matter from the surface portions to harden the same.

13. The method of making fuel briquettes, which includes mixing coal dust and a binder, forcing the mixture through an aperture to form a continuously delivered rod, causing said rod to break up into sections,

and heating said sections to drive off volatile matter from the surface portions to harden the same.

14. The method of forming briquettes which consists in adding a solid Water-solo ble binder to a mixture of oil and finely subdivided solid fuel, forcing the same through an aperture to form a continuouslydelivered rod, breaking the rod into comparatively short sectionsto drive off volatile matter from the surfaceportions, and heating the sections to harden the exterior thereof. a

15. A briquette made by addinga solid i water soluble binder to a mixture of oil and finely subdivided solid fuel, forcingthe same through an aperture to form a con-' tinuously delivered rod, breaking the rod into comparatively short sections to drive off volatile matter from the surface porjtions,-and heating the sections to harden the exterior thereof.

' 16. A briquette in the form ofa section to r of airod havinga substantially smooth peripheral surface and broken end surfaces, the briquette including a solid finely subdivided fuel and a binder, and hardened by.

heating to drive off volatile matter from the surface portion after forming.

Signed at Pennington in the county of Mercer and State of New Jersey this 13 day of September A. D. 1924.

JACOB SHOTWELL ROBE SON. 

